Package dye process

ABSTRACT

A method for kier-dyeing packaged yarn in a discontinuous manner employing a chlorinated solvent as the sole fluid to evacuate the air from the kier and to heat the yarn to achieve dye fixation temperature as the principal vehicle for the dye formulation, and as the means for recovering residual solvent from the dyed yarn packages and kier. The method is practiced by subjecting a kier, which has been loaded with packages of yarn to be dyed, to an initial vacuum followed by introduction of vapors of a chlorinated solvent into the bottom of the kier until the kier is filled with such vapors and substantially all air has been evacuated, discontinuing the exhaustion under vacuum but continuing the introduction of vapors to the kier until the contents achieve the temperature of the vapors, introducing a solvent dyebath into the kier and circulating the dyebath through the kier until the dyebath is spent, removing the spent dyebath from the kier under the pressure of solvent vapors, and circulating the vapors to a heater to superheat the vapors, returning the vapors to the kier, condensing vapors in excess of those necessary to fill the kier and superheater, continuing the circulation of vapors until the solvent is substantially completely removed from the yarn in the kier. Residual solvent is removed by evacuating and purging the kier with an inert gas. Thereafter, the kier is cooled to enable removal of the yarn packages. Finally, solvent is recovered from the spent dyebath and returned to storage.

United States Patent [191 Winn et al.

[ PACKAGE DYE PROCESS [73] Assignee: The Dow Chemical Company,

Midland, Mich.

[22] Filed: Dec. 26, 1973 [21] Appl. No.: 428,299

Related US. Application Data [63] Continuation-impart of Ser. No.296,881, Oct. 12,

1972, abandoned.

52 us. Cl. 8/l49.1, 8/15511' 9/1972 Furness 68/l89 X PrimaryExaminer-Harvey C. l-lornsby Assistant Examiner-Philip R. Coe

Attorney, Agent, or FirmA. Cooper Ancona; Glwynn R. Baker [57] ABSTRACTA method for kier-dyeing packaged yarn in a discon- [451 Mar. 18, 1975tinuous manner employing 'a chlorinated solvent as the sole fluid toevacuate the air from the kier and to heat the yarn to achieve dyefixation temperature as the principal vehicle for the dye formulation,and as the means for recovering residual solvent from the dyed yarnpackages and kier. The method is practiced by subjecting a kier, whichhas been'loaded with packages of yarn to be dyed, toan initial vacuumfollowed by introduction of vapors of a chlorinated solvent into thebottom of the kier until the kier is filled with such vapors andsubstantially all air has been evacuated, discontinuing the exhaustionunder vacuum but continuing the introduction of vapors to the kier untilthe contents achieve the temperature of the vapors, introducing asolvent dyebath into the kier and'circulating the dyebath through thekier until the dyebath is spent, removing the spent dyebath from thekier under the pressure of solvent vapors, and circulating the vapors toa heater to superheat the vapors, returning the vapors to the kier,condensing vapors in excess of those necessary to fill the kier andsuperheater, continuing the circulation of vapors until the solvent issubstantially completely removed from the yarn in the kier. Residualsolvent is removed by evacuating and purging the kier with an inertgas.Thereafter, thekier is cooled to enable removal of'the yarn packages.Fi-

nally, solvent is recovered from the spent dyebath and returned tostorage, 7

t 1 Claim, lDrawing Figure Mar/ ury: 0s

PACKAGE DYE PROCESS CROSS-REFERENCE TO RELATED APPLICATION Thisapplication is a continuation-in-part of our copending application U.S.Ser. No. 296,881 filed Oct. 12, 1972, now abandoned.

BRIEF DESCRIPTION OF THE INVENTION The process of the present inventionis readily understood from the following description with reference tothe drawing.

The kier 1 is opened and loaded with yarn packages IE on the spindles 1Anormally found in yarn package kiers. The kier is closed and sealed,valve V-3 opened and pressure-vacuum compressor 2 is started to beginthe evacuation of air from the kier l. Solvent vapors are generated bydrawing liquid solvent from storage tank 4 through valve V-4 with pump 5into reboiler 6. Hot liquid and vapors exit from reboiler 6 throughvalve V-l into flash liquid separator 9, whence any liquid solvent isrecirculated through valve V-6 to reboiler 6, while the solvent vaporsexit through valve V-l2 and into kier 1. These vapors, continuouslysupplied to kier l, condense on the yarn packages 1B and give up heat.The vapors continue to condense until the kier and yarn packages 1Bachieve the liquid boiling point of the solvent. When this occurs, thevapors, being heavier than air, commence to accumulate in the bottom ofkier l and as they build up, push any remaining air to the vacuumcompressor 2. Any solvent vapors drawn through vacuum compressor 2 arecondensed by condenser 10, collected in accumulator tank 11 and returnedto storage tank 4. When the kier 1 has been totally evacuated of air andis full of vapors, the kier is filled with a solvent dye bath fromexpansion tank 7 (previously made up from solvent in storage tank 4mixed with dye or dye-concentrate in tank 7) by introducing the solventdye bath into the system employing valve V-7, reboiler 6 and valve V-2,which system provides for heating and circulating the solvent dye baththrough the kier with the aid of pump 5. Item 13 is a reversing valvefor the purpose of reversing the direction of flow of dye solutionthrough the kier. One flow direction is indicated by the solid lines,the other by dotted lines.

After sufficient time has elapsed for the yarn packages to be properlydyed and/or the dye has been substantially exhausted from thecirculating solvent, the reboiler 6 is used to further raise thetemperature of the solvent dye bath to create vapors under pressure inthe system, thus forcing the spent solvent bath from the kier and, bymeans of valves V-7 and V-5, into waste storage tank 12.

The next step is drying of the dyed yarn packages in the kier. This isaccomplished by operating the superheater 8 to supply superheated vaporsto the kier l to heat the yarn packages 1B and vaporize liquid solventretained thereby. Simultaneously, the blower 3 is operated to circulatethe superheated vapors, and the condenser 10 and accumulator 11 areoperated to remove vapors in excess of those necessary to fill thesystem.

When there is substantially no more liquid in the system the kier issubjected to evacuation by operating vacuum compressor 2 until theamount of the vapor has been reduced to that obtainable under thevacuum. Then an inert purge gas is introduced into the kier throughvalves V-9 and V-ll to sweep remaining vapors from the kier. The solventvapors thus purgedfrom the kier are condensed by condenser 10, sent toaccumulator 11 and from thence to storage tank 4. The

system is thus freed of residual solvent by the inert gas, after whichthe kier is opened and the dry dyed yarn packages are removed.

Following the entire operation, or, if preferred, during the dryingcycle, spent solvent is reclaimed from storage 12 by using reboiler 6 tosupply heat for flashing the solvent through valve V-l into thevapor-liquid separator 9 under forced circulation by pump 5, the vaporsbeing carried through valve V-13, condensed in condenser 10, collectedin accumulator 11 and finally sent to storage tank 4.

Thus, the improvement in a method of dyeing yarn packages in a kiercomprises l sealing and evacuating a dye kier, (2) introducing into thekier vapors of an organic solvent, which solvent is to be employed asthedye carrier, until the temperature of the kier and its contents areraised to the solvent boiling point, all residual air is expelled andthe kier is filled with said vapors, (3) filling the kier with a solventdyebath which is heated and circulated therethrough until the desireddye fixation temperature is reached and until said dye bath issubstantially exhausted, (4) removing the exhausted dyebath andcirculating solvent vapors to a superheater to provide superheatedvapors to the kier in order to vaporize residual solvent in the yarnpackages, (5) evacuating the kier and purging residual solvent vaporstherein by means of an inert gas, (6) removing the dry dyed yarnpackages and (7) recovering the solvent from the spent (exhausted) dyebath by distillation.

We claim:

1. In a method for dyeing packaged yarn in a discontinuous process bystacking the packaged yarn onto spindlesin a dye kier, filling the kierunder pressure with dye liquor, heating said dye liquor whilecirculating the-same through the kier, draining the spent dye liquorfrom the kier and drying the yarn packages, the improvement whichcomprises:

l. sealing the kier and subjecting the interior to a vacuum,

2. introducing into said evacuated kier vapors of an organic solventwhich is to be employed as the sol.- vent dye vehicle, continuing theintroduction of vapors into said kier until the temperature of the kierand its contents are raised to the solvent boiling point, and the kieris filled with solvent vapors thereby expelling residual air from thekierand its contents,

3. filling the kier with a solvent dyebath which is heated andcirculated through the kier until the desired dye fixation, temperatureis obtained,

4. removing the dyebath, now spent, and circulating vapors from the kierto a heater to raise the temperature of the kier and contents to abovethe boiling point of the dye vehicle, diverting a portion of the vaporsfrom the kier to a condenser, thus removing from the cycle those vaporsin excess of that necessary to fill the kier and the vapor heatingsystem,

5. evacuating and purging the kier with an inert gas to remove residualtraces of solvent vapors,

6. removing the dry dyed yarns, and

7. recovering solvent from the spent dyebath.

1. SEALING THE KIER AND SUBJECTING THE INTERIOR TO A VACUUM,
 1. IN A METHOD FOR DYEING PACKAGED YARN IN A DISCONTINUOUS PROCESS BY STACKING THE PACKAGED YARN ONTO SPINDLES IN A DYE KIER, FILLING THE KIER UNDER PRESSURE WITH DYE LIQUOR, HEATING SAID DYE LIQUOR WHILE CIRCULATING THE SAME THROUGH THE KIER, DRAINING THE SPENT DYE LIQUOR FROM THE KIER AND DRYING THE YARN PACKAGES, THE IMPROVEMENT WHICH COMPRISES:
 2. INTRODUCING INTO SAID EVACUATED KIER VAPORS OF AN ORGANIC SOLVENT WHICH IS TO BE EMPLOYED AS THE SOLVENT DYE VEHICLE, CONTINUING THE INTRODUCTION OF VAPORS INTO SAID KIER UNTIL THE TEMPERATURE OF THE KIER AND ITS CONTENTS ARE RAISED TO THE SOLVENT BOILING POINT,AND THE KIER IS FILLED WITH SOLVENT VAPORS THEREBY EXPELLING RESIDUAL AIR FROM THE KIER AND ITS CONTENTS,
 2. introducing into said evacuated kier vapors of an organic solvent which is to be employed as the solvent dye vehicle, continuing the introduction of vapors into said kier until the temperature of the kier and its contents are raised to the solvent boiling point, and the kier is filled with solvent vapors thereby expelling residual air from the kier and its contents,
 3. filling the kier with a solvent dyebath which is heated and circulated through the kier until the desired dye fixation temperature is obtained,
 3. FILLING THE KIER WITH A SOLVENT DYEBATH WHICH IS HEATED AND CIRCULATED THROUGH THE KIER UNTIL THE DESIRED DYE FIXATION TEMPERATURE IS OBTAINED,
 4. REMOVING THE DYEBATH NOW SPENT, AND CIRCULATING VAPORS FROM THE KIER TO A HEATER TO RAISE THE TEMPERATURE OF THE KIER AND CONTENTS TO ABOVE THE BOILING POINT OF THE DYE VEHICLE, DIVERTING A PORTION OF THE VAPORS FROM THE KIER TO A CONDENSER, THUS REMOVING FROM THE CYCLE THOSE VAPORS IN EXCESS OF THAT NECESSARY TO FILL THE KIER AND THE VAPOR HEATING SYSTEM,
 4. removing the dyebath, now spent, and circulating vapors from the kier to a heater to raise the temperature of the kier and contents to above the boiling point of the dye vehicle, diverting a portion of the vapors from the kier to a condenser, thus removing from the cycle those vapors in excess of that necessary to fill the kier and the vapor heating system,
 5. evacuating and purging the kier with an inert gas to remove residual traces of solvent vapors,
 5. EVACUATING AND PURGING THE KIER WITH AN INERT GAS TO REMOVE RESIDUAL TRACES OF SOLVENT VAPORS,
 6. removing the dry dyed yarns, and
 6. REMOVING THE DRY DYED YARNS, AND
 7. RECOVERING SOLVENT FROM THE SPENT DYEBATH.
 7. recovering solvent from the spent dyebath. 